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The ant in Robert Hooke’s compendium and celebration of microscopy in Micrographia: or Some Physiological Descriptions of Minute Bodies Made by Magnifying Glasses (1665) uniquely resists scientific scrutiny: moving about when alive, too-easily crushed when dead, the ant proves to be insistently difficult to study under a microscope. Through an extended allusion to Richard Ligon’s A True and Exact History of the Island of Barbadoes (1657), Hooke links the unruly ant to the colonial economy of enslaved Africans in Barbados, a place that Ligon understands through sugarcane, enslaved Africans, and saltwater slavery. The story of Hooke’s ant in Micrographia uncovers what Lisa Lowe calls the “intimacy” of modern, Western liberalism and the global conditions upon which it depends. In this case, Hooke’s ant reveals the intimacy of early scientific practice and the institution of transatlantic chattel slavery, exposing in the process that a small thing can reveal vast scales of geography and their networks of exploitation.
The raw materials of “licorice root” in the commerce consist of roots and/or rhizomes (stolons) of different species of Glycyrrhiza. Licorice products and raw materials are frequently mislabeled and often have mixed, misidentified, or unidentified species and parts. This paper provides a detailed comparative analysis of the morpho-anatomies of the rhizomes and roots of five species of Glycyrrhiza, namely G. glabra, G. uralensis, G. echinata, G. inflata, and G. lepidota, by bright-field light microscopy and scanning electron microscopy. The studied species showed some similarities in their basic anatomical features due to the fact that they are phylogenetically closely related and belong to the same genus. However, differences in microscopic features such as the thickness of cork and medullary rays, pore frequency, and size of the vessels were observed. The rhizomes can readily be distinguished by the presence of a distinct pith. The roots lack a well-defined pith and instead have primary xylem in the center.
Bipolar disorder has been repeatedly associated with abnormalities of white matter. However, DTI is intrinsically limited and the precise cellular mechanisms that underlie these alterations remains unknown.
Our aim was to investigate microscopical characteristics of white matter using MRI in patients with bipolar and healthy controls.
77 patients and 71 controls from 3 sites had a T1 structural MRI, a multi-shell HARDI MRI and at one site with a T1-weighted VFA-SPGR acquisition, and a T2 MSME acquisition. The volume fraction and the orientation dispersion was extracted using NODDI from DW images in each site. Myelin Water Fraction was extracted in 33 patients and 36 controls to probe myelin characteristics. White matter bundles were reconstructed using deterministic tractography. Statistical analyses were performed after harmonization by the ComBat algorithm and controlled for age, gender and handedness.
We found significant lower axonal density in patients along the short fibers of the left cingulum, the left anterior arcuate and the left inferior fronto-occipital fasciculus. We found lower mean MWF in patients along the short fibers of the right cingulum, the left inferior fronto-occipital fasciculus, the left anterior arcuate and the splenium of the corpus callosum. We found higher mean orientation dispersion in patients only along the left uncinate fasciculus.
We report alterations of limbic and inter-hemispheric white matter tracts in patients with bipolar disorder reflecting axonal loss, demyelination and architecture alterations. These results contribute to better capture the plurality of the mechanisms involved in bipolar disorder that cannot be deciphered with classical diffusion MRI.
Many universities, commercial companies, and science organizations who use microscopy have outreach programs. The members of such generally love to share their enthusiasm and passion with the next generation. Content and confidence on providing such a program often comes from sharing ideas with like-minded scientists. These programs are typically delegated with the acronym STEM or STEAM: science, technology, engineering, art, and math. One of MSA's outreach programs is ProjectMICRO. Included are some STEAM ideas to share.
This study aimed to reveal the anatomical features of the bovine eye by scanning electron and light microscopic methods. For this purpose, a total of 40 eyes were evaluated. Gross and microscopic characteristics of the cornea, sclera, ciliary body, choroid, iris, and lens were determined. Bowman's and Descemet's membranes of the cornea were quite dense and prominent. Collagen lamellae of the cornea were wavy in the periphery and more parallel to the basal and metachromatic fibroblasts were noted. Three to four ciliary plicae merged to form ciliary processes. The presence of prominent intermediate bands connecting the ciliary plicae was determined. The zonular fibrils merged and attached to the lens in the form of thick zonular bands. A dense corpora nigra was present at the rectangular pupillary border of the iris. Tapetum fibrosum, consisting of polygonal tapetal cells, was in blue-yellow-green color and covered most of the choroid. A complex drainage system consisting of trabecular meshwork, angular aqueous plexus, ciliary sinus, and scleral venous vessels localized in a fairly wide iridocorneal angle was identified. Identifying structural features of the bovine eye is very important and useful for pathological evaluations, understanding species-specific physiological mechanisms and for operative interventions of ruminant species.
Cryo-soft-X-ray tomography is being increasingly used in biological research to study the morphology of cellular compartments and how they change in response to different stimuli, such as viral infections. Segmentation of these compartments is limited by time-consuming manual tools or machine learning algorithms that require extensive time and effort to train. Here we describe Contour, a new, easy-to-use, highly automated segmentation tool that enables accelerated segmentation of tomograms to delineate distinct cellular compartments. Using Contour, cellular structures can be segmented based on their projection intensity and geometrical width by applying a threshold range to the image and excluding noise smaller in width than the cellular compartments of interest. This method is less laborious and less prone to errors from human judgement than current tools that require features to be manually traced, and it does not require training datasets as would machine-learning driven segmentation. We show that high-contrast compartments such as mitochondria, lipid droplets, and features at the cell surface can be easily segmented with this technique in the context of investigating herpes simplex virus 1 infection. Contour can extract geometric measurements from 3D segmented volumes, providing a new method to quantitate cryo-soft-X-ray tomography data. Contour can be freely downloaded at github.com/kamallouisnahas/Contour.
The seventeenth-century microscopists Robert Hooke and Henry Power sought to rhetorically establish the truthfulness of the visual images produced by their instruments, but a counter-rhetoric of visuality was established by Margaret Cavendish in Observations upon Experimental Philosophy (1666). The microscopists’ belief that magnification revealed the truth of nature ran counter to Cavendish’s probabilistic belief that no individual could grasp the infinite truth of nature and sought explanations from the superficies of observed objects rather than the ‘interior figurative motions’ which Cavendish saw as the universal cause of all natural phenomena. While the microscopists emphasized the aesthetic beauty of the micro-visible world, Cavendish emphasized its monstrosity: for her the truth could only be perceived by the ‘natural’ eye observing things in their unmagnified state. Exploiting the microscopists’ complaints about the variability of their images and the defects of their instruments Cavendish redefines the microscopic image as definitively outside the ‘real’.
Advancements in high content image analysis have led to an increase in the adoption of these techniques in basic science and clinical research. High-throughput approaches to imaging and image analysis require minimal user interventions, circumventing the often prohibitively time-consuming and unreliable standard manual analysis. In this study, we demonstrate how high content imaging (HCI) techniques, in combination with high content analysis (HCA), can be paired with more traditional manual analysis to quantify both micro- and macro-level features of biopsied tissue sections. High-resolution, full-color images of stained tissue were acquired and stitched together to reconstruct the entire tissue section, which enabled analyses that required accurate identification of a given region's location within the tissue section. A custom region of interest grid was generated that followed the curvature of the tissue. The composite images were used in two separate analyses: tissue layer thickness as a macro-level approach, and nuclei density as a micro-level approach. Ultimately, the flexibility of the HCI and HCA methodologies used in this study allowed for complex analysis of tissue that would not have been otherwise feasible.
Counting dental acellular cementum (AC) annulations is used to estimate age at death in anthropological contexts by embedding the tooth, sectioning the root, and imaging the thin sections. However, there are several published protocols creating confusion to optimize these steps. We compared three standard illumination techniques (differential interference contrast; transmitted bright field; transmitted polarized) on sections with the same thickness, field of view, on three types of samples: fresh teeth embedded in both MMA and epoxy; archeological samples embedded in epoxy. We compared the quality of AC increment visibility on longitudinal and transversal sections of the same root, to optimize the quality of AC micrographs for age estimation. Results suggest that differential interference contrast microscopy might be ideal, even though brightfield consistently provides a decent image; epoxy resin with quick polymerization time doesn't affect AC structure and allows for higher contrast than traditional MMA; transverse sections are more consistent. These results emphasize the need for cementum-specific procedures not always compatible with traditional dental analyses.
The morphology and composition of the corrosion products of archaeological arsenical copper alloys buried in a specific environment for a long time were investigated using optical microscopy (OM), scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDS), micro X-ray fluorescence (μ-XRF), and X-ray diffraction (XRD). The analyses demonstrated that the alloy composition of the artifacts was copper-arsenic (Cu-AS) with significant amounts of lead in some samples. Cuprite, malachite, and copper (II) hydroxychlorides were observed on a completely mineralized matrix. The surface of the objects was covered by two main corrosion layers formed on the internal cuprous oxide. However, several successive layers of corrosion products were recognized on the artifacts in some cases. Furthermore, phosphatic corrosion products including, mimetite [Pb5(AsO4)3Cl], and pyromorphite [Pb5(PO4)3Cl] were identified. Conichalcite [CaCu(AsO4)](OH), which grew in the form of Liesegang rings, was also identified as a corrosion product of one of the objects. As and Pb exhibited some enrichment in the corrosion crusts of the artifacts. Environmental changes in burial conditions, particularly due to seasonal streams and consequent changes in soil corrosivity, vicinity of objects to bone material, along with the migration of alloy elements, especially lead and arsenic, can explain the morphological features of these archaeological objects.
To compare the efficacy and safety characteristics of endoscopic and microscopic stapes surgery based on current evidence.
A systematic literature search was conducted of three medical databases, focusing on randomised, controlled studies or observational studies. Data related to the efficacy and safety of each technique were extracted. Outcome data were summarised using the pooled mean differences or pooled odds ratios, along with their 95 per cent confidence intervals.
Thirteen studies were included in the meta-analysis. Success rate was evaluated by estimating air–bone gap improvement; this revealed comparable outcomes for the two techniques (mean difference = −0.20; 95 per cent confidence interval = −0.53, 0.14). No statistically significant difference was detected concerning post-operative complications, except for dysgeusia (odds ratio = −1.12; 95 per cent confidence interval = −1.97, −0.28) and pain (odds ratio = −2.00; 95 per cent confidence interval = −2.97, −1.04), which favoured the endoscopic approach.
Though both techniques result in commensurate outcomes concerning success rate, post-operative pain and dysgeusia favour the endoscopic approach. Further high-quality studies are needed to adequately compare the two methods.
Superior semicircular canal dehiscence is an uncommon neurotological disorder in which the petrous temporal bone overlying the superior semicircular canal lacks bone. Its most common symptoms include amplification of internal sounds, autophony, tinnitus, sound- and pressure-induced vertigo, hyperacusis, oscillopsia, and hearing loss. This video presentation aimed to demonstrate endoscopic-assisted repair of superior semicircular canal dehiscence with middle fossa craniotomy.
Eleven patients with superior semicircular canal dehiscence, verified with temporal computed tomography, were enrolled in the study.
An endoscopy-assisted middle fossa approach was applied to all patients. Superior semicircular canal dehiscence was successfully repaired with an endoscope in 11 patients.
Endoscopic-assisted repair of superior semicircular canal dehiscence may be a superior approach compared with binocular operative microscopy.
This paper reports the first case of simultaneous bilateral cochlear implant surgery performed exclusively with a three-dimensional exoscope. It also discusses the optimum operative set-up and the feasibility of three-dimensional exoscopic ear surgery as an alternative to the microscope.
The Vitom three-dimensional exoscope system (Karl Storz) was used.
The surgery was successfully completed, with no peri-operative complications. Both the operation time and the surgical outcome for the patient were comparable with the previous cochlear implant surgical procedures performed in our centre using the conventional operating microscope.
This paper demonstrates that exclusive use of the three-dimensional exoscope is a viable alternative to the operating microscope for selected otological cases. It is clear that the three-dimensional exoscopic technique is potentially very promising for future surgical procedures, provided that cases are selected carefully to prevent compromising exposure, efficiency or patient safety.
Gray-level co-occurrence matrix (GLCM) analysis is a contemporary and innovative computational method for the assessment of textural patterns, applicable in almost any area of microscopy. The aim of our research was to perform the GLCM analysis of cell nuclei in Saccharomyces cerevisiae yeast cells after the induction of sublethal cell damage with ethyl alcohol, and to evaluate the performance of various machine learning (ML) models regarding their ability to separate damaged from intact cells. For each cell nucleus, five GLCM parameters were calculated: angular second moment, inverse difference moment, GLCM contrast, GLCM correlation, and textural variance. Based on the obtained GLCM data, we applied three ML approaches: neural network, random trees, and binomial logistic regression. Statistically significant differences in GLCM features were observed between treated and untreated cells. The multilayer perceptron neural network had the highest classification accuracy. The model also showed a relatively high level of sensitivity and specificity, as well as an excellent discriminatory power in the separation of treated from untreated cells. To the best of our knowledge, this is the first study to demonstrate that it is possible to create a relatively sensitive GLCM-based ML model for the detection of alcohol-induced damage in Saccharomyces cerevisiae cell nuclei.
In response to the requirements imposed by the COVID-19 pandemic in 2020, we developed a remote learning undergraduate workshop for 44 students at the University of Newcastle by embedding scanning electron microscope (SEM) images of Maratus (Peacock) spiders into the MyScope Explore environment. The workshop session had two main components: 1) to use the online MyScope Explore tool to virtually image scales with structural color and pigmented color on Maratus spiders; 2) to join a live SEM session via Zoom to image an actual Maratus spider. In previous years, the undergraduate university students attending this annual workshop would enter the Microscopy Facility at the University of Newcastle to image specimens with SEM; however, in 2020 the Microscopy Facility was closed to student visitors, and this virtual activity was developed in order to proceed with the educational event. The program was highly successful and constitutes a platform that can be used in the future by universities for teaching microscopy remotely.
The mechanics underlying ice–skate friction remain uncertain despite over a century of study. In the 1930s, the theory of self-lubrication from frictional heat supplanted an earlier hypothesis that pressure melting governed skate friction. More recently, researchers have suggested that a layer of abraded wear particles or the presence of quasi-liquid molecular layers on the surface of ice could account for its slipperiness. Here, we assess the dominant hypotheses proposed to govern ice–skate friction and describe experiments conducted in an indoor skating rink aimed to provide observations to test these hypotheses. Our results indicate that the brittle failure of ice under rapid compression plays a strong role. Our observations did not confirm the presence of full-contact water films and are more consistent with the presence of lubricating ice-rich slurries at discontinuous high-pressure zones (HPZs). The presence of ice-rich slurries supporting skates through HPZs merges pressure-melting, abrasion and lubricating films as a unified hypothesis for why skates are so slippery across broad ranges of speeds, temperatures and normal loads. We suggest tribometer experiments to overcome the difficulties of investigating these processes during actual skating trials.
Holotomographic microscopy (HTM) measures the refractive index (RI) tomograms of living cells and tissues in three dimensions. The ability to observe biological processes at high spatial and temporal resolution opens uncharted territories for cell biologists, however, current HTM devices have a limited throughput. We show here the first automated multi-well plate-compatible HTM device, the CX-A. Thanks to state-of-the-art environment control and a new type of autofocus, the CX-A can record multiple conditions in parallel over large fields of view, while its software EVE supports automated single-cell segmentation and quantification. This opens the door to new applications for HTM, from drug screening to systems biology.
This paper provides detailed anatomy and histochemistry of the leaves and stems of Eucalyptus tereticornis illustrated with brightfield and scanning electron microscopy. The key microscopic features that can aid in the species identification include the presence of crust-like epicuticular waxes on the leaf surfaces, platy aggregations of cluster crystals in the epidermal cells, presence of prismatic crystals in the epidermal cells, in the parenchymatous sheath in the blade and petiole, and in the cortex and pith of the stems, and leaf homogenous mesophyll consisting of palisade cells. Histochemical analyses confirmed the presence of lipophilic and phenolic compounds in the contents of secretory cavities, starch grains in the xylem parenchyma of the stem, and lignified elements in the sclerenchymatous ring adjoining the phloem and in the xylem in the leaves and stems.
Methods based on the evaluation of textural patterns in microscopy, such as the “gray-level co-occurrence matrix” (GLCM) analysis are modern and innovative computer and mathematical algorithms that can be used to quantify subtle structural changes in cells and their organelles. Potential application of GLCM method in the fields of psychophysiology and psychiatry to this date has not been systematically investigated. The main objective of our study was to test the existence and strength of the association between chromatin structural organization of peripheral blood neutrophils and levels of self-perceived mental stress. The research was done on a sample of 100 healthy student athletes, and the Depression, Anxiety, and Stress Scales (DASS-21) were used for the estimation of psychological distress. Chromatin textural homogeneity and uniformity were negatively correlated (p < 0.01) with mental distress and had relatively good discriminatory power in differentiating participants with normal and elevated stress levels. As an addition, we propose the creation of a machine learning model based on binomial logistic regression that uses these and other GLCM features to predict stress elevation. To the best of our knowledge, these results are one of the first to establish the link between neutrophil chromatin structural organization quantified by the GLCM method and indicators of normal psychological functioning.
Hancornia speciosa Gomes is popularly known as mangabeira and occurs throughout Brazil. It belongs to the Apocynaceae family and is very important for its food and medicinal uses. The objective of this study was to perform the anatomical and histochemical characterization of the leaves of H. speciosa. Microscope slides were made containing cross sections of petiole and leaf blade, as well as paradermic sections of the leaf blade. The analyses were performed under light and polarized microscopy. For the histochemical analysis, different reagents were used, according to the targeted metabolite. Through microscopic analysis, it was possible to identify the anatomical structures that provide the detailed diagnosis of the studied species. Through histochemistry, the presence of phenolic compounds, tannins, alkaloids, triterpenes and steroids, lipophilic compounds, lignin, starch, and calcium oxalate crystals was evidenced in the leaf blade. Thus, the results presented contribute to the quality control of H. speciosa, as well as to bring unpublished data about the species and to increase knowledge about the Apocynaceae family.